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Multidrug resistance P-glycoprotein monoclonal antibody JSB-1 crossreacts with pyruvate carboxylase.
- Source :
-
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society [J Histochem Cytochem] 1995 Dec; Vol. 43 (12), pp. 1187-92. - Publication Year :
- 1995
-
Abstract
- Multidrug resistance (MDR) is associated with overexpression of a 170 KD plasma membrane P-glycoprotein (P-gp), a putative energy-dependent efflux transporter that reduces intracellular accumulation of chemotherapeutic agents. For detection of P-gp expression in normal and malignant tissues, an MDR1-specific monoclonal antibody (MAb) JSB-1 has been used extensively. In this report we show that MAb JSB-1 crossreacts with a protein of M(r) approximately 130,000 present in rat liver mitochondrial inner membrane/matrix fractions. Peptide mapping and microsequencing identify this protein as pyruvate carboxylase (PC), an abundant mitochondrial enzyme. MAb JSB-1 also crossreacts with purified PC from bovine liver. Under immunoblotting conditions, this crossreactivity is partially abolished by pre-incubation of MAb JSB-1 with a 1000-fold molar excess of MAb C494 epitope-specific peptide (PNTLEGN), indicating that the epitope of MAb JSB-1 may either overlap with or be in close proximity to that of MAb C494. Immunohistochemical cross-reactivity was also demonstrated in cryosections of human skeletal muscle, a tissue known not to express P-gp. MAb JSB-1 strongly immunostained Type 1 fibers, the subtype known to contain abundant mitochondria. Use of MAb JSB-1 for detection of MDR1 P-gp expression should be approached with caution.
- Subjects :
- ATP Binding Cassette Transporter, Subfamily B, Member 1 immunology
Amino Acid Sequence
Animals
Antibodies, Monoclonal immunology
Cattle
Cross Reactions
Drug Resistance, Multiple
Epitopes immunology
False Positive Reactions
Humans
Immunoblotting
Immunohistochemistry
Molecular Sequence Data
Muscles immunology
Muscles metabolism
Pyruvate Carboxylase immunology
Rats
Rats, Sprague-Dawley
ATP Binding Cassette Transporter, Subfamily B, Member 1 analysis
Pyruvate Carboxylase analysis
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1554
- Volume :
- 43
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society
- Publication Type :
- Academic Journal
- Accession number :
- 8537634
- Full Text :
- https://doi.org/10.1177/43.12.8537634